Calibration of automatic potentiometric titrator BY Dr.PIYUSH V. PATEL

Calibration of automatic potentiometric titrator

OBJECTIVE: To provide a procedure for calibration of automatic potentiometric titrator for moisture determination. SCOPE:  Applicable to the automatic potentiometric titrator in Quality Control Department. Model     : AT-38B+KF Manufacturer : Spectralab Sr. No.   : S 302 RESPONSIBILITY: Chemist. PROCEDURE: Turn the instrument & printer on. Repeatability of factor determination. Go to titer mode. Use Disodium tartarate as standard. Take all precautions to avoid variations due to weighing & transfer of standard. Enter sample weight. Find out the factor. Take five readings. Calculate %RSD & average of five. %RSD of five readings should be less than 0.5. Calibration of Burette. Clean the ICB (Inter changeable burette). Fill water in reservoir. Fill the burette. Go to AUX functions & set Eject volume to 0.10ml.
Quit & then press Eject. Collect the volume in clean, dry, & previously weighed beaker. Weigh the beaker & find out the weight of ejected volume, further find out the volume. Volume = Weight in g / 0.99602 Volume should be between 0.0990ml to 0.1010 ml. Fill the burette. Go to AUX functions & set Eject volume to 1.0ml. Quit & then press Eject. Collect the volume in clean, dry, & previously weighed beaker. Weigh the beaker & find out the weight of ejected volume, further find out the volume. Volume = Weight in g / 0.99602 Volume should be between 0.99ml to 1.01 ml. Fill the burette. Go to AUX functions & set Eject volume to 10.0ml. Quit & then press Eject. Collect the volume in clean, dry, & previously weighed beaker. Weigh the beaker & find out the weight of ejected volume, further find out the volume. Volume = Weight in g / 0.99602 Volume should be between 9.98ml to 10.02 ml. Fill the burette. Go to AUX functions & set Eject volume to 20.0ml. Quit & then press Eject. Collect the volume in clean, dry, & pre weighed beaker.
Weigh the beaker & find out the weight of ejected volume, further find out the volume. Volume = Weight in g / 0.99602 Volume should be between 19.97ml to 20.03 ml. Precautions Clean the ICB with acetone after calibration of burette is over. Frequency Once in three months. REFERENCE: User’s guide for Automatic Potentiometric Titrator, Model: AT-38B+KF Indian Pharmacopoeia A] Repeatability of factor determination. Sr. No. Burette Reading (in ml.) Factor Average % RSD 1 2 3 4 5 ACCEPTANCE CRITERIA % RSD Not more than 0.5%. B] Calibration of Burette. Sr. No. Volume (ml.) I II III IV Limit (ml.) Empty Beaker Wt. (g.) Wt. of Beaker + Water (g.) II –I III / 0.99602 1 0.1       0.0990 to 0.1010 2 1.0       0.99 to 1.01 3 10.0       9.98 to 10.02 4 20.0       19.97 to 20.03   CONCLUSION – Calibration Complies / Does not comply as per Standard Calibration Procedure. Next Calibration Due On - Done By : Date : Checked By : Date :